The present invention relates to microwave and higher frequency electronic devices and in particular to a versatile electromechanical device for processing high frequency electric signals and that is readily fabricated using conventional integrated circuit techniques.
The marriage of electrical and mechanical elements to provide for the processing of high frequency electric signals is well-known, for example, as performed by surface acoustic wave (SAW) devices in which the propagation of Rayleigh waves in a piezoelectric solid are used to produce electrical filters, delay lines and transformers. More recently micro electromechanical systems (MEMS) and nanoscale electro-mechanical systems (NEMS) have been used to create mechanical resonators operating in excess of one megahertz for filtration and other purposes. These mechanical devices provide extremely high quality factors (Q) but may require intricate fabrication processes for producing overlapping plates or cantilevered beams suspended above and parallel to a substrate.
U.S. Pat. No. 6,946,693, issued Sep. 20, 2005, naming one of the co-inventors of the present application, assigned to the assignee of the present application and hereby incorporated by reference, describes an electromechanical element in which a nanoscale pillar extending upward from a substrate is excited into mechanical resonance to produce a charge transfer between adjacent conductors at that resonant frequency, used, for example, for switching or filtering. The scale of the pillar is such as to permit megahertz and gigahertz operation. The orientation of the pillar, generally perpendicular to the face of the substrate, permits simple fabrication without the need for undercut elements or the creation of sacrificial support layers.
Practical implementation of MEMS and NEMS megahertz and gigahertz signal processing devices is hampered by the difficulty of communicating signals among the devices and between the devices and external circuit elements.